module cordic 
(
    input                       clk,
    input                       rst_n,
    input             [10:0]    phase,
    output reg signed [31:0]    sin,
    output reg signed [31:0]    cos,
    output reg signed [31:0]    err
);

    //首先是角度的表示，进行了宏定义，360度用16位二进制表示2^16，每一度为2^16/360。
    //360°--2^16,phase = 9bits (input [8:0] phase)
    //1°--2^16/360
    `define rot0  32'd2949120    	//45бу*2^16
    `define rot1  32'd1740992    	//26.5651бу*2^16
    `define rot2  32'd919872    	//14.0362бу*2^16
    `define rot3  32'd466944    	//7.1250бу*2^16
    `define rot4  32'd234368    	//3.5763бу*2^16
    `define rot5  32'd117312    	//1.7899бу*2^16
    `define rot6  32'd58688    	    //0.8952бу*2^16
    `define rot7  32'd29312    	    //0.4476бу*2^16
    `define rot8  32'd14656    	    //0.2238бу*2^16
    `define rot9  32'd7360    		//0.1119бу*2^16
    `define rot10 32'd3648    		//0.0560бу*2^16
    `define rot11 32'd1856			//0.0280бу*2^16
    `define rot12 32'd896    		//0.0140бу*2^16
    `define rot13 32'd448    		//0.0070бу*2^16
    `define rot14 32'd256    		//0.0035бу*2^16
    `define rot15 32'd128    		//0.0018бу*2^16

    parameter PIPELINE = 16;
    parameter K = 32'h09b74;	//K=0.607253*2^16,32'h09b74,

    reg signed 	[31:0] 		x0=0,y0=0,z0=0;
    reg signed 	[31:0] 		x1=0,y1=0,z1=0;
    reg signed 	[31:0] 		x2=0,y2=0,z2=0;
    reg signed 	[31:0] 		x3=0,y3=0,z3=0;
    reg signed 	[31:0] 		x4=0,y4=0,z4=0;
    reg signed 	[31:0] 		x5=0,y5=0,z5=0;
    reg signed 	[31:0] 		x6=0,y6=0,z6=0;
    reg signed 	[31:0] 		x7=0,y7=0,z7=0;
    reg signed 	[31:0] 		x8=0,y8=0,z8=0;
    reg signed 	[31:0] 		x9=0,y9=0,z9=0;
    reg signed 	[31:0] 		x10=0,y10=0,z10=0;
    reg signed 	[31:0] 		x11=0,y11=0,z11=0;
    reg signed 	[31:0] 		x12=0,y12=0,z12=0;
    reg signed 	[31:0] 		x13=0,y13=0,z13=0;
    reg signed 	[31:0] 		x14=0,y14=0,z14=0;
    reg signed 	[31:0] 		x15=0,y15=0,z15=0;
    reg signed 	[31:0] 		x16=0,y16=0,z16=0;
    reg 		[ 1:0] 		Quadrant [PIPELINE:0];

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x0 <= 1'b0; 						
            y0 <= 1'b0;
            z0 <= 1'b0;
        end else begin
            x0 <= K;
            y0 <= 32'd0;
            z0 <= phase[8:0] << 16;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x1 <= 1'b0; 						
            y1 <= 1'b0;
            z1 <= 1'b0;
        end else if(z0[31]) begin
            x1 <= x0 + y0;
            y1 <= y0 - x0;
            z1 <= z0 + `rot0;
        end else begin
            x1 <= x0 - y0;
            y1 <= y0 + x0;
            z1 <= z0 - `rot0;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x2 <= 1'b0; 						
            y2 <= 1'b0;
            z2 <= 1'b0;
        end else if(z1[31]) begin
            x2 <= x1 + (y1 >>> 1);
            y2 <= y1 - (x1 >>> 1);
            z2 <= z1 + `rot1;
        end else begin
            x2 <= x1 - (y1 >>> 1);
            y2 <= y1 + (x1 >>> 1);
            z2 <= z1 - `rot1;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x3 <= 1'b0; 						
            y3 <= 1'b0;
            z3 <= 1'b0;
        end else if(z2[31]) begin
            x3 <= x2 + (y2 >>> 2);
            y3 <= y2 - (x2 >>> 2);
            z3 <= z2 + `rot2;
        end else begin
            x3 <= x2 - (y2 >>> 2);
            y3 <= y2 + (x2 >>> 2);
            z3 <= z2 - `rot2;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x4 <= 1'b0; 						
            y4 <= 1'b0;
            z4 <= 1'b0;
        end else if(z3[31]) begin
            x4 <= x3 + (y3 >>> 3);
            y4 <= y3 - (x3 >>> 3);
            z4 <= z3 + `rot3;
        end else begin
            x4 <= x3 - (y3 >>> 3);
            y4 <= y3 + (x3 >>> 3);
            z4 <= z3 - `rot3;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x5 <= 1'b0; 						
            y5 <= 1'b0;
            z5 <= 1'b0;
        end else if(z4[31]) begin
            x5 <= x4 + (y4 >>> 4);
            y5 <= y4 - (x4 >>> 4);
            z5 <= z4 + `rot4;
        end else begin
            x5 <= x4 - (y4 >>> 4);
            y5 <= y4 + (x4 >>> 4);
            z5 <= z4 - `rot4;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x6 <= 1'b0; 						
            y6 <= 1'b0;
            z6 <= 1'b0;
        end else if(z5[31]) begin
            x6 <= x5 + (y5 >>> 5);
            y6 <= y5 - (x5 >>> 5);
            z6 <= z5 + `rot5;
        end else begin
            x6 <= x5 - (y5 >>> 5);
            y6 <= y5 + (x5 >>> 5);
            z6 <= z5 - `rot5;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x7 <= 1'b0; 						
            y7 <= 1'b0;
            z7 <= 1'b0;
        end else if(z6[31]) begin
            x7 <= x6 + (y6 >>> 6);
            y7 <= y6 - (x6 >>> 6);
            z7 <= z6 + `rot6;
        end else begin
            x7 <= x6 - (y6 >>> 6);
            y7 <= y6 + (x6 >>> 6);
            z7 <= z6 - `rot6;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x8 <= 1'b0; 						
            y8 <= 1'b0;
            z8 <= 1'b0;
        end else if(z7[31]) begin
            x8 <= x7 + (y7 >>> 7);
            y8 <= y7 - (x7 >>> 7);
            z8 <= z7 + `rot7;
        end else begin
            x8 <= x7 - (y7 >>> 7);
            y8 <= y7 + (x7 >>> 7);
            z8 <= z7 - `rot7;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x9 <= 1'b0; 						
            y9 <= 1'b0;
            z9 <= 1'b0;
        end else if(z8[31]) begin
            x9 <= x8 + (y8 >>> 8);
            y9 <= y8 - (x8 >>> 8);
            z9 <= z8 + `rot8;
        end else begin
            x9 <= x8 - (y8 >>> 8);
            y9 <= y8 + (x8 >>> 8);
            z9 <= z8 - `rot8;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x10 <= 1'b0; 						
            y10 <= 1'b0;
            z10 <= 1'b0;
        end else if(z9[31]) begin
            x10 <= x9 + (y9 >>> 9);
            y10 <= y9 - (x9 >>> 9);
            z10 <= z9 + `rot9;
        end else begin
            x10 <= x9 - (y9 >>> 9);
            y10 <= y9 + (x9 >>> 9);
            z10 <= z9 - `rot9;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x11 <= 1'b0; 						
            y11 <= 1'b0;
            z11 <= 1'b0;
        end else if(z10[31]) begin
            x11 <= x10 + (y10 >>> 10);
            y11 <= y10 - (x10 >>> 10);
            z11 <= z10 + `rot10;
        end else begin
            x11 <= x10 - (y10 >>> 10);
            y11 <= y10 + (x10 >>> 10);
            z11 <= z10 - `rot10;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x12 <= 1'b0; 						
            y12 <= 1'b0;
            z12 <= 1'b0;
        end else if(z11[31]) begin
            x12 <= x11 + (y11 >>> 11);
            y12 <= y11 - (x11 >>> 11);
            z12 <= z11 + `rot11;
        end else begin
            x12 <= x11 - (y11 >>> 11);
            y12 <= y11 + (x11 >>> 11);
            z12 <= z11 - `rot11;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x13 <= 1'b0; 						
            y13 <= 1'b0;
            z13 <= 1'b0;
        end else if(z12[31]) begin
            x13 <= x12 + (y12 >>> 12);
            y13 <= y12 - (x12 >>> 12);
            z13 <= z12 + `rot12;
        end else begin
            x13 <= x12 - (y12 >>> 12);
            y13 <= y12 + (x12 >>> 12);
            z13 <= z12 - `rot12;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x14 <= 1'b0; 						
            y14 <= 1'b0;
            z14 <= 1'b0;
        end else if(z13[31]) begin
            x14 <= x13 + (y13 >>> 13);
            y14 <= y13 - (x13 >>> 13);
            z14 <= z13 + `rot13;
        end else begin
            x14 <= x13 - (y13 >>> 13);
            y14 <= y13 + (x13 >>> 13);
            z14 <= z13 - `rot13;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x15 <= 1'b0; 						
            y15 <= 1'b0;
            z15 <= 1'b0;
        end else if(z14[31]) begin
            x15 <= x14 + (y14 >>> 14);
            y15 <= y14 - (x14 >>> 14);
            z15 <= z14 + `rot14;
        end else begin
            x15 <= x14 - (y14 >>> 14);
            y15 <= y14 + (x14 >>> 14);
            z15 <= z14 - `rot14;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            x16 <= 1'b0; 						
            y16 <= 1'b0;
            z16 <= 1'b0;
        end else if(z15[31]) begin
            x16 <= x15 + (y15 >>> 15);
            y16 <= y15 - (x15 >>> 15);
            z16 <= z15 + `rot15;
        end else begin
            x16 <= x15 - (y15 >>> 15);
            y16 <= y15 + (x15 >>> 15);
            z16 <= z15 - `rot15;
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            Quadrant[0] <= 1'b0;
            Quadrant[1] <= 1'b0;
            Quadrant[2] <= 1'b0;
            Quadrant[3] <= 1'b0;
            Quadrant[4] <= 1'b0;
            Quadrant[5] <= 1'b0;
            Quadrant[6] <= 1'b0;
            Quadrant[7] <= 1'b0;
            Quadrant[8] <= 1'b0;
            Quadrant[9] <= 1'b0;
            Quadrant[10] <= 1'b0;
            Quadrant[11] <= 1'b0;
            Quadrant[12] <= 1'b0;
            Quadrant[13] <= 1'b0;
            Quadrant[14] <= 1'b0;
            Quadrant[15] <= 1'b0;
            Quadrant[16] <= 1'b0;
        end else begin
            Quadrant[0] <= phase[10:9];
            Quadrant[1] <= Quadrant[0];
            Quadrant[2] <= Quadrant[1];
            Quadrant[3] <= Quadrant[2];
            Quadrant[4] <= Quadrant[3];
            Quadrant[5] <= Quadrant[4];
            Quadrant[6] <= Quadrant[5];
            Quadrant[7] <= Quadrant[6];
            Quadrant[8] <= Quadrant[7];
            Quadrant[9] <= Quadrant[8];
            Quadrant[10] <= Quadrant[9];
            Quadrant[11] <= Quadrant[10];
            Quadrant[12] <= Quadrant[11];
            Quadrant[13] <= Quadrant[12];
            Quadrant[14] <= Quadrant[13];
            Quadrant[15] <= Quadrant[14];
            Quadrant[16] <= Quadrant[15];
        end
    end

    always @ (posedge clk or negedge rst_n) begin
        if(!rst_n) begin
            cos <= 1'b0;
            sin <= 1'b0;
            err <= 1'b0;
        end else begin
            err <= z16;
            case(Quadrant[16])
                2'b00: //if the Phase is in first Quadrant,the Sin(X)=Sin(A),Cos(X)=Cos(A)
                    begin
                        cos <= x16;
                        sin <= y16;
                    end
                2'b01: //if the Phase is in second Quadrant,the Sin(X)=Sin(A+90)=CosA,Cos(X)=Cos(A+90)=-SinA
                    begin
                        cos <= ~(y16) + 1'b1;//-Sin
                        sin <= x16;//Cos
                    end
                2'b10: //if the Phase is in third Quadrant,the Sin(X)=Sin(A+180)=-SinA,Cos(X)=Cos(A+180)=-CosA
                    begin
                        cos <= ~(x16) + 1'b1;//-Cos
                        sin <= ~(y16) + 1'b1;//-Sin
                    end
                2'b11: //if the Phase is in forth Quadrant,the Sin(X)=Sin(A+270)=-CosA,Cos(X)=Cos(A+270)=SinA
                    begin
                        cos <= y16;//Sin
                        sin <= ~(x16) + 1'b1;//-Cos
                    end
            endcase
        end
    end

endmodule
